2003 Seattle Annual Meeting (November 2–5, 2003)

Paper No. 10
Presentation Time: 8:00 AM-12:00 PM

PRELIMINARY INSPECTION OF WATER QUALITY USING TOTAL COLIFORM AND E.COLI BACTERIA IN THE SENECA LAKE WATERSHED, NY


BECKINGHAM, Barbara A., Department of Chemsitry, Hobart and William Smith Colleges, Geneva, NY 14456 and HALFMAN, John D., Department of Geoscience, Hobart and William Smith Colleges, Geneva, NY 14456, Beckingham@hws.edu

The largest and deepest Finger Lake of central New York State, Seneca Lake supplies over 85,000 people with Class AA drinking water and is thus a crucial economic and recreational resource. Guaranteeing pure, potable water is thereby vital to the livelihood of people and business in the area. Recently, aging municipal and residential wastewater treatment systems and the influx of Concentrated Animal Feedlot Operations (CAFOs) have surfaced as emerging concerns for water quality. Total coliform concentration is a recommended standard for examining water quality because it involves relatively safe, easy, and inexpensive methods which adequately estimate the presence of pathogenic bacteria by indicating the degree of fecal contamination.

Seneca Lake and select streams were analyzed periodically over the summer of 2003 for total coliform and E. coli bacteria using the EPA approved Hach procedure No. 10029. Water samples were diluted, filtered, and incubated in a down-turned Petri-dish on an absorbent pad saturated with m-Coliblue24 Broth at 35oC for 24 hours. Colony forming units (CFUs) were viewed and counted under a low-powered microscope and values multiplied by the dilution factor to reflect concentrations per 100mL.

The general quality of water in Seneca Lake and surrounding streams was sound and in compliance with state regulations. The data do not reveal general trends or relationships between streams on same or different dates. Neither do significant correlations exist between bacteria counts and discharge, total suspended solids, percent land use by watershed area nor nutrient concentrations. A few isolated counts exceeded the maximum monthly median of 2400 CFUs per 100mL set by the NYSDEC for Class A-D water. The isolated high counts may be attributed to wastewater treatment facility failures and other localized sources.

Methods could be improved considering the plethora of potential sources and parameters to be considered. An increased frequency in sampling and the addition of fecal coliform testing may improve the accuracy of data and the conclusions able to be drawn. Individual homeowners concerned about contamination in their water source can contact county, municipal or private laboratories for information and assistance with standard testing or may find it beneficial to install treatment systems in their water supplies.